Integrated circuits are manufactured in a number of discreet steps using a variety of processes and equipment. Due to the differences in these processes and economic factors, different processes may be carried out at different locations throughout the globe.
Semiconductor material may be initially grown in a single crystal in a melt process which typically may be performed in a specialized facility, usually by a dedicated vendor for such processes. Single crystals are then sliced into wafers which may then be further processed in a "FAB" or fabrication facility. In the Fab, the actual circuits may be formed on the semiconductor wafer using a variety of known semiconductor processing processes.
Once each wafer has been formed into circuits, it may then be sent to a facility for final machining, testing, sawing into individual circuits, and packaging. For example, the wafer may first be ground to a desired thickness using a "backgrind" process. Such grinding reduces the thickness of the semiconductor circuit to a desired design size. The wafer may then be sawed or broken into a number of individual chips or circuits. Each chip may then be mounted in a frame or carrier with electrical leads wired-bonded from the carrier to the chip at discrete pad locations.
Finally, the semiconductor chip may be packaged (encapsulated) and labeled to form a final product. During this assembly process, the circuit may be tested at a number of stages to insure that the circuit is functioning properly.
It is with this final assembly process that the present invention is concerned. Various other processes in semiconductor circuit manufacturing are highly automated. For example, the design of an actual circuit, including the various layers, may be sent to a Fab in the form of magnetic tape. Such a tape may be used with computer aided manufacturing equipment to perform the various circuit manufacturing steps on a semiconductor wafer.
However, the final assembly process has remained a largely manually programmable process to date. FIG. 1 is a block diagram illustrating the relationship between data elements used in assembling a semiconductor device 180. When data is transmitted to a semiconductor assembly facility (which may typically be located overseas), such data may be transmitted manually in the form of paper documents. Discrete data representing backgrind thickness 125, wire bonding pattern 135, chip size and packaging 145, and identification marking 165, may be provided in discrete separate documents. Each of these documents may be listed in table for a particular part model number comprising an assembly release code specification 115.
When assembling a particular semiconductor device, local Engineers may enter data for a particular part (and revision) number, retrieving data from the various documents 115, 125, 135, 145, and 165 provided by the product designer.
Unfortunately, as semiconductor part numbers may be confusingly similar (or may go through several revisions, Rev. A, Rev. B, and the like) the data for each step in the assembly process may become confused by the end user with disastrous results. An improperly ground part, or a part improperly wire bonded may not function properly. Moreover, a mis-marked part, although functional, may be as worthless as a defective part, as the end user will not be able to discern the correct part number for that part, and thus the intended functionality.
Moreover, even if such data is properly received and correlated, it remains a requirement for the assembly operation to manually program each machine in the process with such data to properly process the semiconductor wafers into assembled chips.
Thus, it remains a requirement in the art to provide a method for transmitting disparate assembly data for a semiconductor device to an assembly operation such that assembly data for different discrete steps is received in a coherent and comprehensive fashion.
Moreover, it remains a requirement in the art to provide a method for programming assembly equipment with assembly data for a semiconductor part such that assembly and packaging of such a part may be automated.